A device of the kind specified is described in U.S. Pat. No. 4,493,036 (and in the corresponding French Patent Publication FR 2 493 446 A). In those documents it has been proposed that the resilient plates should be juxtaposed with each other and arranged "head to toe", i.e. displaced from each other through an angle of 180.degree., so as to avoid any displacement of the centre of the assembly during operation.
Even so, such an arrangement is not entirely satisfactory. This arises from the fact that, although the resultant forces brought into play are radially opposed to each other as between one resilient plate and the other, there is a damaging tilting moment, in axial planes, due to the axial displacement between one resilient plate and the next. For example, when the resilient plates are coupled with a sliding hub for rotation therewith, there is a risk of the hub becoming jammed. This is due to the fact that one of the resilient plates exerts a radial force on one axial end of the hub in an upper part of the latter, while the other resilient plate exerts a radial force in the opposite direction on the lower part of the hub at its other axial end.
The same is true when the hub, as part of one of the two coaxial parts of the clutch, is mounted on the bearing interposed between the hub and a support member constituting part of the other coaxial part of the clutch, the tilting moment then setting up stresses which are detrimental, particularly to the life expectancy of the bearing.